Part A: In order to find the x-intercepts, you should set f(x)=0. Then, . and .
Part B: From the function, it is visible that it is going to be a minimum, because the function is cup-size. Vertex coordinates can be calculated by the formula . Then and . The vertex coordinates are (-1.25, -0.125)
Part C: By using the vertex coordinates, we can construct the vertex of the function and then using the information about the x-intercept we can complete the function. The function looks like in the picture below.
Part A: In order to find the x-intercepts, you should set f(x)=0. Then, . and .
Part B: From the function, it is visible that it is going to be a minimum, because the function is cup-size. Vertex coordinates can be calculated by the formula . Then and . The vertex coordinates are (-1.25, -0.125)
Part C: By using the vertex coordinates, we can construct the vertex of the function and then using the information about the x-intercept we can complete the function. The function looks like in the picture below.
What you see in the z score table is P(z< a constant), for P( z≥ a number), subtract the probability from 1: 1-0.1587=0.8413 on the z score table, you will see that p(z<1.00)=0.8413 so c=1.00